Apparatus for laying off or ascertaining ships&#39; courses



H. BRYN'GE AND H. HAMMAR.

APPARATUS FOR LAYING OFF OR ASCEHTAINING SHIPS COURSES.

APPLICATION FILED AUG.28| I917.

1 ,330,839. Patented Feb. 17, 1920.

2 SHEETS-SHEET I- 6171 1192; 5: M W E W im/ml Attorney.

H. BRYNGE AND H. HAMMAR.

APPARATUS FOR LAYING OFF 08 ASCERTAINING SHIPS COURSES.

, APPLICATION FILED AUG.28,191I. 1,330,839.

Patented Feb. 17,1920.

2 SHEETS-SHEET 2.

Ivwsntors: er y Attorney.

UNITED STATES PATENT OFFICE.

HANNES BRYNGE, OF ENKUPING, AND HARRY HAMMAR, 0F STOGKHOLM, SWEDEN.

APPARATUS FOR LAYING OFF OR ASCER-TAINING SHIPS" COURSES.

Application filed August 28, 1917.

To all whom it may concern:

Be it known that we, HANNEs BRYNGE and HARRY HAMMAR, subjects of theKing of Sweden, residing the former at Enkoping, Sweden, and the latterat Stockholm, Sweden, have invented new and useful Improvements inApparatus for Laying Off or Ascertaining Ships Courses, of which thefollowing is a specification.

The present invention relates to navigating instruments and moreparticularly to devices for laying ofi the course of a ship.

The objects of our invention are to produce a device which is itselfsimple and inexpensive and at the same time accurate and trustworthy,and by means of which the true course may be determined with a minimumof calculation.

In the accompanying drawing our invention is illustrated, Figure 1presenting one form, and Figs. 2 and 3 a modification thereof in planview and cross section respectively.

The construction according to Fig. 1 consists of a transparent plate 1,provided with two straight edges 5, 6, perpendicular to each other, andon this plate is printed or engraved a circular scale of degrees 2 and acircular scale of points 3, arranged in such a manner that the quartersof wind are reversed. In the construction illustrated in Fig. 1 each ofthe straight edges 5, 6 is parallel with a line passing through oppo-'site cardinal points and one of the edges is provided with notches 7 todistinguish it from the other. The center 4 of the circular scales isindicated in a suitable manner, for instance, by means of two lines,perpendicular to each other. That ruler-edge 5, which is parallel to theline joining cardinal points E\V, may appropriately be provided with theword Latitude, while the other edge 6 is marked Longitude, thesignificance of these terms being apparent from the method of usehereinafter described.

On the nautical chart a ruler is laid along the course line, which is tobe determined, and then the one ruler-edgefor instance 5of the apparatusis brought into contact with the ruler and moved along the same untilthe center 4 falls above a latitude. The course is then directly readoff on the apparatus at the place where the latitude on the chartcrosses the scale 2 on the plate 1. If the other ruler-edge 6 is used,the course is to be read off by means of a longitude. ShouldSpecification of Letters Patent.

Patented Feb. 17, 1920.

Serial No. 188,687,

the apparatus be used only for a certain place it might sometimes besuitable to arrange the scale or scales in such an angle or relation tothe ruler-edge or -edges that the course obtained at once will becorrected for the declination.

In the construction as illustrated in Figs. 2 and 3 a movable pointer isprovided and also a circular plate concentric to the scale, the pointerbeing provided with indicating lines and the circular plate with a scaleto indicate declination.

Such a construction is illustrated in Figs. 2 and 3, wherein 9 is thepivotally mounted, transparent pointer-plate with the indicating line10, the zero line on the scale and the declination-scale 11 at bothsides of the line 10. A second trans )arent pointer 12 ment of Fig. 1,the circular plate 9 is turned in such a manner that the indicating line10 coincides with the latitude or the longitude. Then the apparatus maybe removed from the chart and the pointer 12 be turned to indicate thedeclination on the declination scale 11, for which reason the pointer 12also is provided with an indicating line 16. The true course hereafteris to be read off on the scales 22 or 28 by means of the pointer 12.Correction for deviation may be done either simultaneously with that forthe declination or afterward. Thus in Figs. 2 and 3 the true course canbe obtained after the course is read off on the chart.

Common for all the apparatus according to the present invention is thatthe circular scale or scales are arranged at the same plate, which isprovided with the ruler-edge or edges, so that it will not be possiblefor the scale to turn in relation to the ruleredge or -edges, thuspreventing all mistakes by reading off the apparatus.

Having now particularly described the nature of our invention and themanner of its operation, what we claim is:

1. A navigating instrument consisting of an integral transparent platehaving a straight ruler edge, said plate having an inverted compassscale marked thereon, the positions of the signs East and \Vest beingreversed 'Wlth respect to the northsouth line-the line joining cardinalpoints of said scale being parallel to the, said ruler edge of theplate, and a center mark at the center of the scale. 1

2. A navigating instrument consisting of an integral transparent platehaving two perpendicular straight edges, said plate having an invertedcompass scale mar ed thereon-the positions or the signs East and Westbelng reversed wlth respect to the V north*south linethe lines joiningopposite cardinal points of said scale being parstraight edges, aninverted compass scale on nal points of said scale being parallel to thestraight edges of the plate, a center mark at the center of the scale, acircular plate concentric With said scale and movable about the centerthereof, said circular plate being provided with a zero point and degreemarks, and a pointer superposed thereon and movable aboutthe center ofthe scale independently of both of said plates.

In testimony whereof We have signed our names to this specification inthe presence of tWo subscribing Witnesses.

HANNES BRYNGE. HARRY HAMMAR. Witnesses H. W. HARRIs, JACOB 'BAGGE.

